Portable flat seat



FIG. 1 is a perspective view of a portable flat seat;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a front view thereof; and,

FIG. 7 is a back view thereof.

The broken lines shown in the FIG. 1 drawing view are for illustrative purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a portable flat seat, as shown and described. 